Method of making paints.



UNITED STATES PATENT OFFICE.

ALEXANDER S. RAMAGE,- OF BUFFALO, NEW YORK, ASSIGNOR TO THE CHEMICAL DEVELOPMENT 00., OF BUFFALO, NEW YORK, A CORPORATION OF COLORADO.

METHOD OF MAKING PAINTS.

No Drawing.

To all whom it may concern:

Be it known that 'I, ALEXANDER S. BAM- AGE, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Methods of Making Paints, of which the following is a specification.

This invention relates to. the preparation' of paints, printing inks and like compositions, the object of the invention being the provision of a method wherein the expensive steps of washing. and drying the pigment and grinding the same in oil are either completely eliminated or so modified as greatly to reduce the time and cost ofthe operation.

The present method is applicable to all pigments without exception, whether freshly preci itated or dry, and to a wide variety of ve icles; and the product is superzor in quality to paints as heretofore prepared.

The method will be described by reference 'to certain specific embodiments thereof, it being understood that the invention is not thereby limited.

According to thepreferred mode of practicing the invention the pigment, suspended in or mixed with water, is intimately mixed with a suitable soap, usually a stearate or oleate soap or a mixture of these, the soap being previously dissolved. A suitable proportion of soap is approximately thirty per cent. by weight of the amount of pigment taken, although more or less than this pro portion may be used with satisfactory results. The mixture may be moderately heated, boiling temperatures being avoided. In case of certain pigments, as the basic lead salts, including red lead, areaction occurs whereby lead soaps are formed, whereas with other pigments no such reaction occurs at this stage of the process, or only to a negligible extent. In all cases any excess of soap in solution is precipitated as an insoluble metallic soap by adding a solution of a metallic salt, usually but not necessarily a-salt of the metal of the pigment, the mixture being well stirred. The precipitate is curdy in character and subsides quickly. The liquoris decanted and the precipitate or curd thrown onto a screen or filter which may be of cheesecloth. It is rapidly washed on the screen,usually with a hose, and the Specification of Letters Patent.

Application flledAugust 22, 1910. Serial No. 578,469. 4

Patented Sept. 26, 1911.

kettle, preferably provided with stirring arms an ordinary soap-boilers kettle being suitable. In the kettle the curd is melted and stirred until the water is eliminated,as

indicated b a state of quiet'fusion. There is then ad ed directly to the melted mass such proportion of linseed oil or other appropriate vehicle that the mixture when cooled remains as athin can be further thinned with oil or turpentine or wit use as a aint.

For tie preparation of a paint from Prussian blue, for example, the procedure may be as follows: To a solution of ferrocyanid of sodium or potassium is added a stearate or oleate soa in the proportion of 30% by weight of tie precipitate of iron ferrocyanid, and the mixture 1S added to an equivalent amount of ferrous sulfate. To the resultin mixture is added with stirring an excess 0 a ferric salt, as the sulfate or chlorid, serving to precipitate the soap and also to oxidize the precipitated iron salt.

The resulting precipitate consisting of a ferric soap and Prussian blue is curdy in character provided the temperature has not exceeded 100 C., and is filtered off and washed in the filter, pressed, heated to quiet fusion and mixed with oil precisely as above described. The resulting paste may if desired be thinned with lithographic varnish for production of-a' printing ink, no milling being required or effective to secure a finer subdivision of the pigment than is obtainable by the simple procedure above described.

In thepreparation of printing inks it is desirable to add linseed oil soap' to the stearate or oleate soap. In practice it is preferred to use equal proportions of linseed and oleate soaps, precipitating the excess soap with a lead salt.

For the production of yellow chromes, bichromate of potassium or sodium in solution is nearly neutralized by sodium carbonate, and the required proportion of paste. This pasterosin varnish and is ready for stearate or oleate soap is added; preferably stant stirring, the amount of lead acetate ormed. This solution is then being sufiicient to precipitate the entire quantity of soap.- The resulting curdy precipitate is treated as above described.

- ments,

By a. combination of the two methods. above described any desired shade of green may be obtained. V

In the preparation ,of paints from pigments which are affected by traces of alkali, as for example Prussian blue, yellow chromes or L greens containing these pigit is necessary to observe special pre cautions in the preparation of the soap to used for salting out. When these soaps .are

metal of the pigment used, as ferric avoid 'the presence therein of free alkali.

Somewhat less caustic soda than is required for complete saponification should be used, so that the soap will contain a slight excess of fat, and common salt alone should be the oxid is mixed with water and with thirty per cent. or more of' its weight of stearate or oleate soap or a mixture of these; The soap is then thrown down by addition of a metallic salt, preferably'a salt of the salts with iron oxid pigments, etc. However, lead acetate may be used for precipitation of is followed, zinc sulfate being preferably part or all of the soap, where light colors or a quick drying paint is desired.

In the case of red and white lead, these are heated with 'a soap solution in the proportion of one-fourth to one-half or more of soap by weight ofthe pigment, and the excess of soap is precipitated by a suitable salt, as lead acetate or alum. In the case of zinc oxid or litho'pone .the same procedure used as the precipitant.-

I In the case of Venetian reds, ochers, umbers, siennas and other; pigments containing usually about 50% by weight of the pigment, and is precipitated by the calcium calcium compounds, the soap,.preferably an olcate soap, is added in'proper proportion,

. i I salts. In such cases it 1s usually unnecessary to use anextraneous precipitant. The 'sub-. sequent procedure is as in the foregoing cases) The paints prepared; as above described yield films which are water-repellent, and are capable of enduring prolonged exposure to weather conditions without" becoming chalky or absorbent or showing other evi-' dences of "deterioration; They- ,may be thinned with turpentine, naphtha or even rosin varnishes for the preparation of ready imixed paints, and do not settle into hardmasses or cake on standing.

The curdy precipitate consisting essentially of :the pigment and an insoluble metallic soap formed in presence of the pigment and intimately associated therewith is Water-repellent and may be washed with the utmost ease; and, as above pointed out, it may be simply melted and mixed with oil instead of being subjected to prolonged grinding therewith in in previous processes.

a dry or wet state as I By reason of. the

elimination of the slow processes of washing, drying and grinding the pigments, and mixing and grinding the same with oil, the present, method is highly economical and rapid as compared with the processes as I heretofore practiced.

I claim: a 1. The method of making paints and like compositions, which consists in compounding a suitable paint vehicle with a pigment and an insoluble metallic soap while said soap is rendered fluid by the aid of heat.

' 2. The method of making paints and like compositions, a metallic soap inp res'ence of a pigment, drying and melting the mixture, and com pounding therewith a suitablepaint vehicle.

3. The method of making paints and like compositions, which consists in simultaneously precipitating a pigment and an insoluble metallic soap, the product, and compounding. therewith a suitable paint vehicle. v

r In testimony whereof, I aflix my signature in presence of two witnesses.

ALEXANDER S. RAMAGE. Witnesses: a C. P. TOWNSEND,

E. A. BYRNES.

which consists in precipitating drying and melting 

